• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1656-1661
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• 2012

UV inspection technology is being used for predictive maintenance of power facility together with IR-thermography and ultrasonic devices. In this paper, the UV corona camera design, fabrication, and perform a simple test to be take advantage of the diagnostic equipment. The UV corona camera developed a $6.4^{\circ}{\times}4.8^{\circ}$ of the field of view as a conventional camera to diagnose a wide range of slightly enlarged, and power equipment to measure the distance between the camera and the distance meter has been attached. The transmission between 250 to 280nm was 11% ($12.5%{\times}88%{\times}98%$) by combing the transmission on absorption film, window and other filter(UG 5, nickel sulphate and so on). In a distance of 5m with the UV corona camera it is possible to detect partial discharge with a PD level of 2.5pC and a RIV level of $3.6dB{\mu}V$.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.91-91
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• 2012

We aim in synthesizing various functional thin films thinner than ~ 10 nm for environmental applications and photovoltaic devices. Atomic layer deposition is used for synthesizing inorganic thin films with a precise control of the film thickness. Several examples about application of our thin films for removing volatile organic compounds (VOC) will be highlighted, which are summarized in the below. 1) $TiO_2$ thin films prepared by ALD at low temperature ($<100^{\circ}C$) show high adsorption capacity for toluene. In combination with nanostructured templates, $TiO_2$ thin films can be used as building-block of high-performing VOC filter. 2) $TiO_2$ thin films on carbon fibers and nanodiamonds annealed at high temperatures are active for photocatalytic oxidation of VOCs, i.e. photocatalytic filter can be created by atomic layer deposition. 3) NiO can catalyze oxidation of toluene to $CO_2$ and $H_2O$ at $<300^{\circ}C$. $TiO_2$ thin films on NiO can reduce poisoning of NiO surfaces by reaction intermediates below $200^{\circ}C$. We also fabricated inverted organic solar cell based on ZnO electron collecting layers on ITO. $TiO_2$ thin films with a mean diameter less than 3 nm on ZnO can enhance photovoltaic performance by reducing electron-hole recombination on ZnO surfaces.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.56-59
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• 1997

SAW filters of transversal type were fabricated on some piezoelectric substrates of the LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$Y-X, Quartz ST-cut wafers through the simulation in which the number o: IDT and window function were changed for the required frequency, and the mask making. Their IDT spacing and width were 3 ${\mu}{\textrm}{m}$, chip size was 4.462 $\times$ 2.086 mm$^2$, and they had double electrode transversal type IDTs. In addition to pure Al electrode devices, Ti thin films having the different thicknesses was introduced between the Al electrode and the substrate for improving the power resistance strength. They had 11-12 dB insertion losses similar to those of pure Al electrode SAW filters in case of LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$ Y-X, meaning that Ti thin film was not detrimental to the insertion loss and general frequency properties. The filters had the center frequencies 162MHz for LN 128$^{\circ}$ Y-X, 186MHz for 64$^{\circ}$ Y-X, and 131MHz for Quartz ST-cut substrates.

• Journal of IKEEE
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• v.23 no.2
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• pp.407-412
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• 2019

Many industrial regions has used and extended the application of LED driver because of many advantage. Specially, due to the simplicity, miniaturization and power density, the flyback converter is selected by a lot of power engineer. Also, the electrolytic capacitor in this converter is used for the constant DC voltage of the converter because of the sufficient capacitance and the economic price. However, because of the characteristics of the electrolytic capacitor and ripple currents on the converter. the expected lifetime of the LED driver is more and more shorted. In this paper, a single-stage CCM PFC flyback converter with the film capacitor is suggested to extended the lifetime of the LED driver. In addition, the proposed converter with the LC filter is decreased the ripple current of the converter output.

• Journal of Sensor Science and Technology
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• v.32 no.1
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• pp.16-21
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• 2023

This study reports the potential of using commercial copy papers as substrates for simple sensitive glucose detection. Typical paper-based devices use filter papers as porous substrates that can contain reagents; however, this is the first study to report the use of copy papers for the purpose of enhancing enzymatic colorimetric detection. Glucose detection using glucose oxidase, horseradish peroxidase and potassium iodide was performed on a copy paper, cellulose-based filter paper, and polyethylene film. The results indicated that the copy paper exhibited a stronger coloration than the other substrates. Reagents required for detection were dried on the copy paper, and a 3D-printed holder was designed to provide an environment for consistent imaging, making it a convenient cost-effective option for point-of-care testing using a mobile phone camera. The simple paper-based glucose sensor exhibited a linear range of 0.1-20 mM, limit of quantification of 0.477 mM, and limit of detection of 0.143 mM.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.4
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• pp.247-254
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• 2012

Vitrification technology has been widely applied as one of effective processing methods for wastes generated in nuclear power plants. The advantage of vitrifying for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. Recently, a filter using on HVAC(Heating Ventilating & Air Conditioning System) is composed with media (glass fiber) and separator (aluminum film) has been studied the proper treatment technology for meeting the waste disposal requirement. Present paper is a feasibility study for the filter vitrification that developing of the glass compositions for filter melting and melting test for physicochemical characteristic evaluation. The aluminum metal of film type is preparing with 0.5 cm size for proper mixing with glass frit, glass fiber is also preparing with 1 cm size within crucible. The glass compositions should be developed considering molten glass are related with wastes reduction. Glass compositions obtained from developing on glass formulation are mainly composed of $SiO_2$ and $B_2O_3$ for aluminum metal. A variety of factors obtained from the glass formulation and melting test are reviewed, which is feeding rate and glass characteristics of final products such as durability for implementing the wastes disposal requirement.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.807-809
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• 2009

Thin film deposition methods have been widely used and intensively investigated because high quality crystalline films enable to fabricate by sputtering. Especially rf magnetron sputtering deposition has advantages of being employ a relatively high deposition rate and also to achieve high crystalline films in low pressure because plasma density around target by magnetic is high. To apply ZnO thin film for SAW filter, it has highly flat surface, excellent c-axis preferred orientation and high resistivity value. As-deposited ZnO films showed the strong c-axis growth and excellent crystallinity. C-axis preferred orientation, resistivity and surface roughness highly depended on oxygen/argon gas ratio.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.5
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• pp.16-22
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• 2011

This paper presents the multi-object tracking approach using the background difference and particle filtering by monte carlo sampling. We apply particle filters based on probabilistic importance sampling to multi-object independently. We formulate the object observation model by the histogram distribution using color information and the object dynaminc model for the object motion information. Our approach does not increase computational complexity and derive stable performance. We implement the whole Bayesian maximum likelihood framework and describes robust methods coping with the real-world object tracking situation by the observation and transition model.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.88-91
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• 2003

Electromagnetic interference shielding and near-infrared cutoff filters for plasma display panel application were designed and fabricated by radio frequency magnetron sputtering. Three types of the filters were prepared: the basic structure of type A consisted of [$TiO_2$ Ti Ag $TiO_2$]; type B, of [$TiO_2$ ITO Ag $TiO_2$]; type C, of [$TiO_2$ ITO Ag ITO $TiO_2$]. Ti and ITO layers deposited on Ag layers were employed as barriers to prevent the oxidation and the diffusion of Ag film into the adjacent oxide layers. Optical, electrical, chemical, and structural properties were investigated, and the result shows that the filters with the ITO barrier layers provided an enhancement in transmittance in the visible owing to a lower absorption of ITO layers than Ti layers. Type C filter showed better optical and electrical performances and smoother surface roughness than Type B and C filters: the average sheet resistance was as low as 1.51 $\Omega\Box$ (where $\square$ stands for a square film), the peak transmittance in the visible was as high as 78.2 %, and the average surface roughness was 1.48 nm.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.2
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• pp.41-51
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• 2014

This paper describes a method to estimate the noise power using the minimum statistics approach, which was originally proposed for audio processing. The proposed minimum statistics-based method separates a noisy image into multiple frequency bands using the three-level discrete wavelet transform. By assuming that the output of the high-pass filter contains both signal detail and noise, the proposed algorithm extracts the region of pure noise from the high frequency band using an appropriate threshold. The region of pure noise, which is free from the signal detail part and the DC component, is well suited for minimum statistics condition, where the noise power can be extracted easily. The proposed algorithm reduces the computational load significantly through the use of a simple processing architecture without iteration with an estimation accuracy greater than 90% for strong noise at 0 to 40dB SNR of the input image. Furthermore, the well restored image can be obtained using the estimated noise power information in parametric image restoration algorithms, such as the classical parametric Wiener or ForWaRD image restoration filters. The experimental results show that the proposed algorithm can estimate the noise power accurately, and is particularly suitable for fast, low-cost image restoration or enhancement applications.